Signaling design of enhanced handover support for drones in a cellular network

ABSTRACT

To configure a UT for handover between a source evolved Node-B (eNB) and a target eNB using aerial communications in a cellular network, the UE processing circuitry is to decode measurement configuration information from the source eNB. The measurement configuration information includes a plurality of height thresholds associated with aerial height of the UE. A measurement report is encoded for transmission to the source eNB. The measurement report includes the aerial height of the UE and the measurement report generation triggered based on one or more triggering events associated with the plurality of height thresholds. RRC signaling from the source eNB is decoded, the RRC signaling including a handover command. The handover command is based on a handover decision by the source eNB using the measurement report. A handover from the source eNB to the target eNB is performed based on the handover command.

PRIORITY CLAIM

This application is a continuation of U.S. patent application Ser. No.16/274,865, filed Feb. 13, 2019, which claims the benefit of priority tothe U.S. Provisional Patent Application Ser. No. 62/631,325, filed Feb.15, 2018, and entitled “METHOD AND SIGNALING DESIGN OF ENHANCED HANDOVERSUPPORT FOR DRONES IN A CELLULAR NETWORK,” which patent applications areincorporated herein by reference in their entirety.

TECHNICAL FIELD

Aspects pertain to wireless communications. Some aspects relate towireless networks including 3GPP (Third Generation Partnership Project)networks, 3GPP LTE (Long Term Evolution) networks, 3GPP LTE-A (LTEAdvanced) networks, and fifth-generation (5G) networks including 5G newradio (NR) (or 5G-NR) networks and 5G-LTE networks. Other aspects aredirected to systems and methods for signaling design of enhancedhandover support for aerial user equipment (UE), such as a drone US, ina cellular network.

BACKGROUND

Mobile communications have evolved significantly from early voicesystems to today's highly sophisticated integrated communicationplatform. With the increase in different types of devices communicatingwith various network devices, the usage of 3GPP LTE systems hasincreased. The penetration of mobile devices (user equipment or UEs) inmodern society has continued to drive demand for a wide variety ofnetworked devices in a number of disparate environments. Fifthgeneration (5G) wireless systems are forthcoming and are expected toenable even greater speed, connectivity, and usability. Next generation5G networks (or NR networks) are expected to increase throughput,coverage, and robustness and reduce latency and operational and capitalexpenditures. 5G-NR networks will continue to evolve based on 3GPPLTE-Advanced with additional potential new radio access technologies(RATs) to enrich people's lives with seamless wireless connectivitysolutions delivering fast, rich content and services. As currentcellular network frequency is saturated, higher frequencies, such asmillimeter wave (mmWave) frequency, can be beneficial due to their highbandwidth.

Potential LTE operation in the unlicensed spectrum includes (and is notlimited to) the LTE operation in the unlicensed spectrum via dualconnectivity (DC), or DC-based LAA, and the standalone LTE system in theunlicensed spectrum, according to which LTE-based technology solelyoperates in the unlicensed spectrum without requiring an “anchor” in thelicensed spectrum, called MulteFire. MulteFire combines the performancebenefits of LTE technology with the simplicity of Wi-Fi-likedeployments.

Further enhanced operation of LTE systems in the licensed as well asunlicensed spectrum is expected in future releases and 5G systems. Suchenhanced operations can include techniques to address the signalingdesign of enhanced handover support for aerial UEs, such as drones, in acellular network.

BRIEF DESCRIPTION OF THE FIGURES

In the figures, which are not necessarily drawn to scale, like numeralsmay describe similar components in different views. Like numerals havingdifferent letter suffixes may represent different instances of similarcomponents. The figures illustrate generally, by way of example, but notby way of limitation, various aspects discussed in the present document.

FIG. 1A illustrates an architecture of a network, in accordance withsome aspects.

FIG. 1B is a simplified diagram of an overall next generation (NG)system architecture, in accordance with some aspects.

FIG. 1C illustrates a functional split between next generation radioaccess network (NG-RAN) and the 5G Core network (5GC), in accordancewith some aspects.

FIG. 1D illustrates an example Evolved Universal Terrestrial RadioAccess (E-UTRA) New Radio Dual Connectivity (EN-DC) architecture, inaccordance with some aspects.

FIG. 2 illustrates a geographical heat map of UE reference signalreceived power (RSRP) from a 1^(st) sector (boresight pointing 30°towards upper right) of a central base station (BS) site for UEs at 0 mand 300 m altitudes.

FIG. 3 illustrates a communication flow diagram for handover usingmeasurement reporting with enhanced signaling design for drones in acellular network, in accordance with some aspects.

FIG. 4 illustrates a block diagram of an example measurement report thatcan be configured using enhanced signaling design for drones, inaccordance with some aspects.

FIG. 5 illustrates a block diagram of a communication device such as anevolved Node-B (eNB), a new generation Node-B (gNB), an access point(AP), a wireless station (STA), a mobile station (MS), or a userequipment (UE) such as a drone, in accordance with some aspects.

DETAILED DESCRIPTION

The following description and the drawings sufficiently illustrateaspects to enable those skilled in the art to practice them. Otheraspects may incorporate structural, logical, electrical, process, andother changes. Portions and features of some aspects may be included in,or substituted for, those of other aspects. Aspects set forth in theclaims encompass all available equivalents of those claims.

FIG. 1A illustrates an architecture of a network in accordance with someaspects. The network 140A is shown to include user equipment (UE) 101and UE 102. The UEs 101 and 102 are illustrated as smartphones (e.g.,handheld touchscreen mobile computing devices connectable to one or morecellular networks) but may also include any mobile or non-mobilecomputing device, such as Personal Data Assistants (PDAs), pagers,laptop computers, desktop computers, wireless handsets, drones, or anyother computing device including a wired and/or wireless communicationsinterface. The UEs 101 and 102 can be collectively referred to herein asUE 101, and UE 101 can be used to perform one or more of the techniquesdisclosed herein.

Any of the radio links described herein (e.g., as used in the network140A or any other illustrated network) may operate according to anyexemplary radio communication technology and/or standard.

LTE and LTE-Advanced are standards for wireless communications ofhigh-speed data for UE such as mobile telephones. In LTE-Advanced andvarious wireless systems, carrier aggregation is a technology accordingto which multiple carrier signals operating on different frequencies maybe used to carry communications for a single UE, thus increasing thebandwidth available to a single device. In some aspects, carrieraggregation may be used where one or more component carriers operate onunlicensed frequencies.

There are emerging interests in the operation of LTE systems in theunlicensed spectrum. As a result, an important enhancement for LTE in3GPP Release 13 has been to enable its operation in the unlicensedspectrum via Licensed-Assisted Access (LAA), which expands the systembandwidth by utilizing the flexible carrier aggregation (CA) frameworkintroduced by the LTE-Advanced system. Rel-13 LAA system focuses on thedesign of downlink operation on the unlicensed spectrum via CA, whileRel-14 enhanced LAA (eLAA) system focuses on the design of uplinkoperation on the unlicensed spectrum via CA.

Aspects described herein can be used in the context of any spectrummanagement scheme including, for example, dedicated licensed spectrum,unlicensed spectrum, (licensed) shared spectrum (such as Licensed SharedAccess (LSA) in 2.3-2.4 GHz, 3.4-3.6 GHz, 3.6-3.8 GHz, and furtherfrequencies and Spectrum Access System (SAS) in 3.55-3.7 GHz and furtherfrequencies). Applicable exemplary spectrum bands include IMT(International Mobile Telecommunications) spectrum (including 450-470MHz, 790-960 MHz, 1710-2025 MHz, 2110-2200 MHz, 2300-2400 MHz, 2500-2690MHz, 698-790 MHz, 610-790 MHz, 3400-3600 MHz, to name a few),IMT-advanced spectrum, IMT-2020 spectrum (expected to include 3600-3800MHz, 3.5 GHz bands, 700 MHz bands, bands within the 24.25-86 GHz range,for example), spectrum made available under the Federal CommunicationsCommission's “Spectrum Frontier” 5G initiative (including 27.5-28.35GHz, 29.1-29.25 GHz, 31-31.3 GHz, 37-38.6 GHz, 38.6-40 GHz, 42-42.5 GHz,57-64 GHz, 71-76 GHz, 81-86 GHz and 92-94 GHz, etc), the ITS(Intelligent Transport Systems) band of 5.9 GHz (typically 5.85-5.925GHz) and 63-64 GHz, bands currently allocated to WiGig such as WiGigBand 1 (57.24-59.40 GHz), WiGig Band 2 (59.40-61.56 GHz), WiGig Band 3(61.56-63.72 GHz), and WiGig Band 4 (63.72-65.88 GHz); the 70.2 GHz-71GHz band; any band between 65.88 GHz and 71 GHz; bands currentlyallocated to automotive radar applications such as 76-81 GHz; and futurebands including 94-300 GHz and above. Furthermore, the scheme can beused on a secondary basis on bands such as the TV White Space bands(typically below 790 MHz) wherein particular the 400 MHz and 700 MHzbands can be employed. Besides cellular applications, specificapplications for vertical markets may be addressed, such as PMSE(Program Making and Special Events), medical, health, surgery,automotive, low-latency, drones, and the like.

Aspects described herein can also be applied to different Single Carrieror OFDM flavors (CP-OFDM, SC-FDMA, SC-OFDM, filter bank-basedmulticarrier (FBMC), OFDMA, etc.) and in particular 3GPP NR (New Radio)by allocating the OFDM carrier data bit vectors to the correspondingsymbol resources.

In some aspects, any of the UEs 101 and 102 can comprise anInternet-of-Things (IoT) UE or a Cellular IoT (CIoT) UE, which cancomprise a network access layer designed for low-power IoT applicationsutilizing short-lived UE connections. In some aspects, any of the UEs101 and 102 can include a narrowband (NB) IoT UE (e.g., such as anenhanced NB-IoT (eNB-IoT) UE and Further Enhanced (FeNB-IoT) UE). An IoTUE can utilize technologies such as machine-to-machine (M2M) ormachine-type communications (MTC) for exchanging data with an MTC serveror device via a public land mobile network (PLMN), Proximity-BasedService (ProSe) or device-to-device (D2D) communication, sensornetworks, or IoT networks. The M2M or MTC exchange of data may be amachine-initiated exchange of data. An IoT network includesinterconnecting IoT UEs, which may include uniquely identifiableembedded computing devices (within the Internet infrastructure), withshort-lived connections. The IoT UEs may execute background applications(e.g., keep-alive messages, status updates, etc.) to facilitate theconnections of the IoT network.

In some aspects, NB-IoT devices can be configured to operate in a singlephysical resource block (PRB) and may be instructed to retune twodifferent PRBs within the system bandwidth. In some aspects, an eNB-IoTUE can be configured to acquire system information in one PRB, and thenit can retune to a different PRB to receive or transmit data.

In some aspects, any of the UEs 101 and 102 can include enhanced MTC(eMTC) UEs or further enhanced MTC (FeMTC) UEs.

The UEs 101 and 102 may be configured to connect, e.g., communicativelycouple, with a radio access network (RAN) 110. The RAN 110 may be, forexample, an Evolved Universal Mobile Telecommunications System (UMTS)Terrestrial Radio Access Network (E-UTRAN), a NextGen RAN (NG RAN), orsome other type of RAN. The UEs 101 and 102 utilize connections 103 and104, respectively, each of which comprises a physical communicationsinterface or layer (discussed in further detail below); in this example,the connections 103 and 104 are illustrated as an air interface toenable communicative coupling, and can be consistent with cellularcommunications protocols, such as a Global System for MobileCommunications (GSM) protocol, a code-division multiple access (CDMA)network protocol, a Push-to-Talk (PTT) protocol, a PTT over Cellular(POC) protocol, a Universal Mobile Telecommunications System (UMTS)protocol, a 3GPP Long Term Evolution (LTE) protocol, a fifth generation(5G) protocol, a New Radio (NR) protocol, and the like.

In some aspects, the network 140A can include a core network (CN) 120.Various aspects of NG RAN and NG Core are discussed herein in referenceto, e.g., FIG. 1B, FIG. 1C, and FIG. 1D.

In an aspect, the UEs 101 and 102 may further directly exchangecommunication data via a ProSe interface 105. The ProSe interface 105may alternatively be referred to as a sidelink interface comprising oneor more logical channels, including but not limited to a PhysicalSidelink Control Channel (PSCCH), a Physical Sidelink Shared Channel(PSDCH), a Physical Sidelink Discovery Channel (PSDCH), and a PhysicalSidelink Broadcast Channel (PSDCH).

The UE 102 is shown to be configured to access an access point (AP) 106via connection 107. The connection 107 can comprise a local wirelessconnection, such as, for example, a connection consistent with any IEEE802.11 protocol, according to which the AP 106 can comprise a wirelessfidelity (WiFi®) router. In this example, the AP 106 is shown to beconnected to the Internet without connecting to the core network of thewireless system (described in further detail below).

The RAN 110 can include one or more access nodes that enable theconnections 103 and 104. These access nodes (ANs) can be referred to asbase stations (BSs), NodeBs, evolved NodeBs (eNBs), Next GenerationNodeBs (gNBs), RAN nodes, and the like, and can comprise ground stations(e.g., terrestrial access points) or satellite stations providingcoverage within a geographic area (e.g., a cell). In some aspects,communication nodes 111 and 112 can be transmission/reception points(TRPs). In instances when the communication nodes 111 and 112 are NodeBs(e.g., eNBs or gNBs), one or more TRPs can function within thecommunication cell of the NodeBs. The RAN 110 may include one or moreRAN nodes for providing macrocells, e.g., macro RAN node 111, and one ormore RAN nodes for providing femtocells or picocells (e.g., cells havingsmaller coverage areas, smaller user capacity, or higher bandwidthcompared to macrocells), e.g., low power (LP) RAN node 112.

Any of the RAN nodes 111 and 112 can terminate the air interfaceprotocol and can be the first point of contact for the UEs 101 and 102.In some aspects, any of the RAN nodes 111 and 112 can fulfill variouslogical functions for the RAN 110 including, but not limited to, radionetwork controller (RNC) functions such as radio bearer management,uplink and downlink dynamic radio resource management and data packetscheduling, and mobility management. In an example, any of the nodes 111and/or 112 can be a new generation node-B (gNB), an evolved node-B(eNB), or another type of RAN node.

In accordance with some aspects, the UEs 101 and 102 can be configuredto communicate using Orthogonal Frequency-Division Multiplexing (OFDM)communication signals with each other or with any of the RAN nodes 111and 112 over a multicarrier communication channel in accordance variouscommunication techniques, such as, but not limited to, an OrthogonalFrequency-Division Multiple Access (OFDMA) communication technique(e.g., for downlink communications) or a Single Carrier FrequencyDivision Multiple Access (SC-FDMA) communication technique (e.g., foruplink and ProSe for sidelink communications), although such aspects arenot required. The OFDM signals can comprise a plurality of orthogonalsubcarriers.

In some aspects, a downlink resource grid can be used for downlinktransmissions from any of the RAN nodes 111 and 112 to the UEs 101 and102, while uplink transmissions can utilize similar techniques. The gridcan be a time-frequency grid, called a resource grid or time-frequencyresource grid, which is the physical resource in the downlink in eachslot. Such a time-frequency plane representation may be used for OFDMsystems, which makes it applicable for radio resource allocation. Eachcolumn and each row of the resource grid may correspond to one OFDMsymbol and one OFDM subcarrier, respectively. The duration of theresource grid in the time domain may correspond to one slot in a radioframe. The smallest time-frequency unit in a resource grid may bedenoted as a resource element. Each resource grid may comprise a numberof resource blocks, which describe the mapping of certain physicalchannels to resource elements. Each resource block may comprise acollection of resource elements; in the frequency domain, this may, insome aspects, represent the smallest quantity of resources thatcurrently can be allocated. There may be several different physicaldownlink channels that are conveyed using such resource blocks.

The physical downlink shared channel (PDSCH) may carry user data andhigher-layer signaling to the UEs 101 and 102. The physical downlinkcontrol channel (PDCCH) may carry information about the transport formatand resource allocations related to the PDSCH channel, among otherthings. It may also inform the UEs 101 and 102 about the transportformat, resource allocation, and H-ARQ (Hybrid Automatic Repeat Request)information related to the uplink shared channel. Typically, downlinkscheduling (assigning control and shared channel resource blocks to theUE 102 within a cell) may be performed at any of the RAN nodes 111 and112 based on channel quality information fed back from any of the UEs101 and 102. The downlink resource assignment information may be sent onthe PDCCH used for (e.g., assigned to) each of the UEs 101 and 102.

The PDCCH may use control channel elements (CCEs) to convey the controlinformation. Before being mapped to resource elements, the PDCCHcomplex-valued symbols may first be organized into quadruplets, whichmay then be permuted using a sub-block interleaver for rate matching.Each PDCCH may be transmitted using one or more of these CCEs, whereeach CCE may correspond to nine sets of four physical resource elementsknown as resource element groups (REGs). Four Quadrature Phase ShiftKeying (QPSK) symbols may be mapped to each REG. The PDCCH can betransmitted using one or more CCEs, depending on the size of thedownlink control information (DCI) and the channel condition. There canbe four or more different PDCCH formats defined in LTE with differentnumbers of CCEs (e.g., aggregation level, L=1, 2, 4, or 8).

Some aspects may use concepts for resource allocation for controlchannel information that are an extension of the above-describedconcepts. For example, some aspects may utilize an enhanced physicaldownlink control channel (EPDCCH) that uses PDSCH resources for controlinformation transmission. The EPDCCH may be transmitted using one ormore enhanced control channel elements (ECCEs). Similar to above, eachECCE may correspond to nine sets of four physical resource elementsknown as an enhanced resource element groups (EREGs). An ECCE may haveother numbers of EREGs according to some arrangements.

The RAN 110 is shown to be communicatively coupled to a core network(CN) 120 via an S1 interface 113. In aspects, the CN 120 may be anevolved packet core (EPC) network, a NextGen Packet Core (NPC) network,or some other type of CN (e.g., as illustrated in reference to FIGS.1B-1I). In this aspect, the S1 interface 113 is split into two parts:the S1-U interface 114, which carries traffic data between the RAN nodes111 and 112 and the serving gateway (S-GW) 122, and the S1-mobilitymanagement entity (MME) interface 115, which is a signaling interfacebetween the RAN nodes 111 and 112 and MMEs 121.

In this aspect, the CN 120 comprises the MMEs 121, the S-GW 122, thePacket Data Network (PDN) Gateway (P-GW) 123, and a home subscriberserver (HSS) 124. The MMEs 121 may be similar in function to the controlplane of legacy Serving General Packet Radio Service (GPRS) SupportNodes (SGSN). The MMEs 121 may manage mobility aspects in access such asgateway selection and tracking area list management. The HSS 124 maycomprise a database for network users, including subscription-relatedinformation to support the network entities' handling of communicationsessions. The CN 120 may comprise one or several HSSs 124, depending onthe number of mobile subscribers, on the capacity of the equipment, onthe organization of the network, etc. For example, the HSS 124 canprovide support for routing/roaming, authentication, authorization,naming/addressing resolution, location dependencies, etc.

The S-GW 122 may terminate the S1 interface 113 towards the RAN 110, androutes data packets between the RAN 110 and the CN 120. In addition, theS-GW 122 may be a local mobility anchor point for inter-RAN nodehandovers and also may provide an anchor for inter-3GPP mobility. Otherresponsibilities of the S-GW 122 may include a lawful intercept,charging, and some policy enforcement.

The P-GW 123 may terminate an SGi interface toward a PDN. The P-GW 123may route data packets between the EPC network 120 and external networkssuch as a network including the application server 184 (alternativelyreferred to as application function (AF)) via an Internet Protocol (IP)interface 125. The P-GW 123 can also communicate data to other externalnetworks 131A, which can include the Internet, IP multimedia subsystem(IPS) network, and other networks. Generally, the application server 184may be an element offering applications that use IP bearer resourceswith the core network (e.g., UMTS Packet Services (PS) domain, LTE PSdata services, etc.). In this aspect, the P-GW 123 is shown to becommunicatively coupled to an application server 184 via an IP interface125. The application server 184 can also be configured to support one ormore communication services (e.g., Voice-over-Internet Protocol (VoIP)sessions, PTT sessions, group communication sessions, social networkingservices, etc.) for the UEs 101 and 102 via the CN 120.

The P-GW 123 may further be a node for policy enforcement and chargingdata collection. Policy and Charging Rules Function (PCRF) 126 is thepolicy and charging control element of the CN 120. In a non-roamingscenario, in some aspects, there may be a single PCRF in the Home PublicLand Mobile Network (HPLMN) associated with a UE's Internet ProtocolConnectivity Access Network (IP-CAN) session. In a roaming scenario witha local breakout of traffic, there may be two PCRFs associated with aUE's IP-CAN session: a Home PCRF (H-PCRF) within an HPLMN and a VisitedPCRF (V-PCRF) within a Visited Public Land Mobile Network (VPLMN). ThePCRF 126 may be communicatively coupled to the application server 184via the P-GW 123. The application server 184 may signal the PCRF 126 toindicate a new service flow and select the appropriate Quality ofService (QoS) and charging parameters. The PCRF 126 may provision thisrule into a Policy and Charging Enforcement Function (PCEF) (not shown)with the appropriate traffic flow template (TFT) and QoS class ofidentifier (QCI), which commences the QoS and charging as specified bythe application server 184.

In an example, any of the nodes 111 or 112 can be configured tocommunicate to the UEs 101, 102 (e.g., dynamically) an antenna panelselection and a receive (Rx) beam selection that can be used by the UEfor data reception on a physical downlink shared channel (PDSCH) as wellas for channel state information reference signal (CSI-RS) measurementsand channel state information (CSI) calculation.

In an example, any of the nodes 111 or 112 can be configured tocommunicate to the UEs 101, 102 (e.g., dynamically) an antenna panelselection and a transmit (Tx) beam selection that can be used by the UEfor data transmission on a physical uplink shared channel (PUSCH) aswell as for sounding reference signal (SRS) transmission.

In some aspects, the communication network 140A can be an IoT network.One of the current enablers of IoT is the narrowband-IoT (NB-IoT).NB-IoT has objectives such as coverage extension, UE complexityreduction, long battery lifetime, and backward compatibility with theLTE network. In addition, NB-IoT aims to offer deployment flexibilityallowing an operator to introduce NB-IoT using a small portion of itsexisting available spectrum, and operate in one of the following threemodalities: (a) standalone deployment (the network operates in re-farmedGSM spectrum); (b) in-band deployment (the network operates within theLTE channel); and (c) guard-band deployment (the network operates in theguard band of legacy LTE channels). In some aspects, such as withfurther enhanced NB-IoT (FeNB-IoT), support for NB-IoT in small cellscan be provided (e.g., in microcell, picocell or femtocell deployments).One of the challenges NB-IoT systems face for small cell support is theUL/DL link imbalance, where for small cells the base stations have lowerpower available compared to macro-cells, and, consequently, the DLcoverage can be affected and/or reduced. In addition, some NB-IoT UEscan be configured to transmit at maximum power if repetitions are usedfor UL transmission. This may result in large inter-cell interference indense small cell deployments.

In some aspects, the UE 101 can support connectivity to a 5G corenetwork (5GCN) and can be configured to operate with Early DataTransmission (EDT) in a communication architecture that supports one ormore of Machine Type Communications (MTC), enhanced MTC (eMTC), furtherenhanced MTC (feMTC), even further enhanced MTC (efeMTC), and narrowbandInternet-of-Things (NB-IoT) communications. When operating with EDT, aphysical random access channel (PRACH) procedure message 3 (MSG3) can beused to carry the short uplink (UL) data and PRACH procedure message 4(MSG4) can be used to carry short downlink (DL) data (if any isavailable). When a UE wants to make a new RRC connection, it firsttransmits one or more preambles, which can be referred to as PRACHprocedure message 1 (MSG1). The MSG4 can also indicate UE to immediatelygo to IDLE mode. For this purpose, the transport block size (TBS)scheduled by the UL grant received for the MSG3 to transmit UL data forEDT needs to be larger than the TBS scheduled by the legacy grant. Insome aspects, the UE can indicate its intention of using the early datatransmission via MSG1 using a separate PRACH resource partition. FromMSG1, eNB knows that it has to provide a grant scheduling TBS valuesthat may differ from legacy TBS for MSG3 in the random-access response(RAR or MSG2) so that the UE can transmit UL data in MSG3 for EDT.However, the eNB may not exactly know what would be the size of UL datathe UE wants to transmit for EDT and how large a UL grant for MSG3 wouldbe needed, though a minimum and a maximum TBS for the UL grant could bedefined. The following two scenarios may occur: (a) The UL grantprovided in RAR is larger than the UL data plus header. In this case,layer 1 needs to add one or more padding bits in the remaining grant.However, transmitting a large number of padding bits (or useless bits)is not power efficient especially in deep coverage where a larger numberof repetitions of transmission is required. (b) Similarly, when the ULgrant provided in RAR is large but falls short to accommodate the ULdata for the EDT, the UE may have to send only the legacy RRC message tofallback to legacy RRC connection. In this case, UE may again need totransmit a number of padding bits, which can be inefficient.

As used herein, the term “PRACH procedure” can be used interchangeablywith the term “Random Access procedure” or “RA procedure”.

In some aspects and as described hereinbelow, the UE 101 (and 102) canbe configured for aerial communications in a cellular network. In thisregard, UE 101 can be implemented within a vehicle or it can be a drone.In some aspects, techniques disclosed herein can be used for enhancedhandover support when the UE 101 is configured for aerial communications(e.g., when the UE 101 is a drone) in a cellular network. Morespecifically, UE 101 can be configured for measurement reporting usingmeasurement configuration information 190A received from eNB 111. Inresponse, UE 101 can perform measurement reporting and generate ameasurement report 192A for communication to the eNB 111. Themeasurement report 192A can include signaling, as discussed hereinbelow,which can be used for enhanced handover support. Additionally, corenetwork 120 can include a database 194A with 3D signal environmentproperties which can be used for enhanced handover support as discussedherein.

FIG. 1B is a simplified diagram of a next generation (NG) systemarchitecture 140B in accordance with some aspects. Referring to FIG. 1B,the NG system architecture 140B includes RAN 110 and a 5G network core(5GC) 120. The NG-RAN 110 can include a plurality of nodes, such as gNBs128 and NG-eNBs 130.

The core network 120 (e.g., a 5G core network or 5GC) can include anaccess and mobility function (AMF) 132 and/or a user plane function(UPF) 134. The AMF 132 and the UPF 134 can be communicatively coupled tothe gNBs 128 and the NG-eNBs 130 via NG interfaces. More specifically,in some aspects, the gNBs 128 and the NG-eNBs 130 can be connected tothe AMF 132 by NG-C interfaces, and to the UPF 134 by NG-U interfaces.The gNBs 128 and the NG-eNBs 130 can be coupled to each other via Xninterfaces.

In some aspects, a gNB 128 can include a node providing new radio (NR)user plane and control plane protocol termination towards the UE and isconnected via the NG interface to the 5GC 120. In some aspects, anNG-eNB 130 can include a node providing evolved universal terrestrialradio access (E-UTRA) user plane and control plane protocol terminationstowards the UE and is connected via the NG interface to the 5GC 120.

In some aspects, the NG system architecture 140B can use referencepoints between various nodes as provided by 3GPP Technical Specification(TS) 23.501 (e.g., V15.4.0, 2018-12).

In some aspects, each of the gNBs 128 and the NG-eNBs 130 can beimplemented as a base station, a mobile edge server, a small cell, ahome eNB, and so forth.

In some aspects, node 128 can be a master node (MN) and node 130 can bea secondary node (SN) in a 5G architecture. The MN 128 can be connectedto the AMF 132 via an NG-C interface and to the SN 128 via an XN-Cinterface. The MN 128 can be connected to the UPF 134 via an NG-Uinterface and to the SN 128 via an XN-U interface.

FIG. 1C illustrates a functional split between NG-RAN and the 5G Core(5GC) in accordance with some aspects. Referring to FIG. 1C, there isillustrated a more detailed diagram of the functionalities that can beperformed by the gNBs 128 and the NG-eNBs 130 within the NG-RAN 110, aswell as the AMF 132, the UPF 134, and the SMF 136 within the 5GC 120. Insome aspects, the 5GC 120 can provide access to the Internet 138 to oneor more devices via the NG-RAN 110.

In some aspects, the gNBs 128 and the NG-eNBs 130 can be configured tohost the following functions: functions for Radio Resource Management(e.g., inter-cell radio resource management 129A, radio bearer control129B, connection mobility control 129C, radio admission control 129D,dynamic allocation of resources to UEs in both uplink and downlink(scheduling) 129F); IP header compression, encryption and integrityprotection of data; selection of an AMF at UE attachment when no routingto an AMF can be determined from the information provided by the UE;routing of User Plane data towards UPF(s); routing of Control Planeinformation towards AMF; connection setup and release; scheduling andtransmission of paging messages (originated from the AMF); schedulingand transmission of system broadcast information (originated from theAMF or Operation and Maintenance); measurement and measurement reportingconfiguration for mobility and scheduling 129E; transport level packetmarking in the uplink; session management; support of network slicing;QoS flow management and mapping to data radio bearers; support of UEs inRRC_INACTIVE state; distribution function for non-access stratum (NAS)messages; radio access network sharing; dual connectivity; and tightinterworking between NR and E-UTRA, to name a few.

In some aspects, the AMF 132 can be configured to host the followingfunctions, for example: NAS signaling termination; NAS signalingsecurity 133A; access stratum (AS) security control; inter-core network(CN) node signaling for mobility between 3GPP access networks; idlestate/mode mobility handling 133B, including mobile device, such as a UEreachability (e.g., control and execution of paging retransmission);registration area management; support of intra-system and inter-systemmobility; access authentication; access authorization including check ofroaming rights; mobility management control (subscription and policies);support of network slicing; and/or SMF selection, among other functions.

The UPF 134 can be configured to host the following functions, forexample: mobility anchoring 135A (e.g., anchor point forIntra-/Inter-RAT mobility); packet data unit (PDU) handling 135B (e.g.,external PDU session point of interconnect to data network); packetrouting and forwarding; packet inspection and user plane part of policyrule enforcement; traffic usage reporting; uplink classifier to supportrouting traffic flows to a data network; branching point to supportmulti-homed PDU session; QoS handling for user plane, e.g., packetfiltering, gating, UL/DL rate enforcement; uplink traffic verification(SDF to QoS flow mapping); and/or downlink packet buffering and downlinkdata notification triggering, among other functions.

The Session Management function (SMF) 136 can be configured to host thefollowing functions, for example: session management; UE IP addressallocation and management 137A; selection and control of user planefunction (UPF); PDU session control 137B, including configuring trafficsteering at UPF 134 to route traffic to proper destination; control partof policy enforcement and QoS; and/or downlink data notification, amongother functions.

FIG. 1D illustrates an example Evolved Universal Terrestrial RadioAccess (E-UTRA) New Radio Dual Connectivity (EN-DC) architecture, inaccordance with some aspects. Referring to FIG. 1D, the EN-DCarchitecture 140D includes radio access network (or E-TRA network, orE-TRAN) 110 and EPC 120. The EPC 120 can include MMEs 121 and S-GWs 122.The E-UTRAN 110 can include nodes 111 (e.g., eNBs) as well as EvolvedUniversal Terrestrial Radio Access New Radio (EN) next generationevolved Node-Bs (en-gNBs) 128.

In some aspects, en-gNBs 128 can be configured to provide NR user planeand control plane protocol terminations towards the UE 102 and acting asSecondary Nodes (or SgNBs) in the EN-DC communication architecture 140D.The eNBs 111 can be configured as master nodes (or MeNBs) and the eNBs128 can be configured as secondary nodes (or SgNBs) in the EN-DCcommunication architecture 140D. As illustrated in FIG. 1D, the to eNBs111 are connected to the EPC 120 via the S1 interface and to the EN-gNBs128 via the X2 interface. The EN-gNBs (or SgNBs) 128 may be connected tothe EPC 120 via the S1-U interface, and to other EN-gNBs via the X2-Uinterface. The SgNB 128 can communicate with the UE 102 via a UUinterface (e.g., using signaling radio bearer type 3, or SRB3communications as illustrated in FIG. 1D), and with the MeNB 111 via anX2 interface (e.g., X2-C interface). The MeNB 111 can communicate withthe UE 102 via a UU interface.

Even though FIG. 1D is described in connection with EN-DC communicationenvironment, other types of dual connectivity communicationarchitectures (e.g., when the UE 102 is connected to a master node and asecondary node) can also use the techniques disclosed herein.

In some aspects, the MeNB 111 can be connected to the MME 121 via S1-MMEinterface and to the SgNB 128 via an X2-C interface. In some aspects,the MeNB 111 can be connected to the SGW 122 via S1-U interface and tothe SgNB 128 via an X2-U interface. In some aspects associated with dualconnectivity (DC) and/or MultiRate-DC (MR-DC), the Master eNB (MeNB) canoffload user plane traffic to the Secondary gNB (SgNB) via split beareror SCG (Secondary Cell Group) split bearer.

There is growing interest in utilizing cellular networks to providecommunications for emerging drone applications. However, cellularnetworks were developed to serve user equipment (UE) on the ground andhence there are multiple challenges to support drone communications viacellular links. For example, the path loss for ground-to-air channeldecays slower than a ground-to-ground channel. Thus, drones canexperience severe co-channel interference from multiple neighbor cells.It is possible that there are certain regions in the air where thesignal quality (e.g., signal-to-interference-plus-noise ratio or SINR)is very low to maintain a control channel connection causing radio linkfailure (RLF). In addition, base station (BS) antennas are typicallytilted downwards for better ground coverage. Due to the fact that dronesare supported by the side lobes of the BS antennas, BS-drone linkqualities can fluctuate from side lobe to side lobe as drones travel inthe sky. Depending on its speed, the drone may encounter ping-pongissues in handover (HO), i.e. HO back and forth with the same BS.Without carefully considering the anticipated cell quality fluctuation,an unnecessary HO procedure may be triggered. This is also true when adrone does fast maneuvers like flipping/rotation with directionalantenna patterns. In most instances, the handover failure rate increaseswith drone speed and altitude. As maintaining a reliable command andcontrol channel is essential for drone operation, it is of criticalimportance to improve the handover performance for drones.

Techniques disclosed herein can use characteristics of dronecommunication channels for enhancing HO support of drones. In thisregard, both BS/network-initiated and UE-initiated enhancementprocedures are disclosed herein, with proposed new signaling that can beuseful for handover support for drones. More specifically, two kinds ofdrone handover enhancement approaches are disclosed hereinbelow: (a)Base station/network-initiated mobility enhancements; and (b)UE-initiated specific mobility enhancement. For both enhancements, newhandover algorithms are designed addressing special drone channelproperties, and new signaling can be used to cope with the mobilitymanagement for drones.

Drone Special Channel Properties

Although the channel environment for drones is more hostile, it is morepredictable as there are fewer objects in the sky. Therefore, there aremore opportunities to take advantage of these predictable features. FIG.2 illustrates a geographical heat map of UE reference signal receivedpower (RSRP) from a 1^(st) sector (boresight pointing 30° towards upperright) of a central base station (BS) site for UEs at 0 m and 300 maltitudes. We can observe that, for aerial UEs (at 300 m heightillustrated at graph 204), signal attenuates slower as the distance toBS increases than ground UEs (at 0 m illustrated at graph 202), i.e., aBS can cause strong interference to UEs located in neighboring cellsthat are one or two tiers beyond. In addition, there can be drops insignal level due to elevation null from BS antenna pattern. Failure totimely detect the sudden signal drop can result in handover failure orRLF. On the other hand, since the signals may quickly recover once theUE travels back to regions with good signal quality, there can beunnecessary HO being triggered. The frequent transition between high andlow signal strength can translate to more cell boundaries a UE observeswhile moving around. Therefore, aerial UEs (or drones) can experiencemore frequent handovers than ground UEs and may suffer from ping-pongeffect.

Nevertheless, we can observe clear signal strength variation patternfrom FIG. 2 for aerial UEs. This implies that we can make use of extrainformation, such as UE geolocation, speed, and travel direction, topredict the corresponding channel response and enhance the handoverprocedure for drones. In the following paragraphs, there is providedadditional information regarding techniques for enhancing handover fordrones.

Base Station/Network—Initiated Mobility Enhancement:

Algorithm:

In some aspects, a cell can maintain 3-dimensional signal environmentproperties in a database (e.g., database 194A), which records thequality of the signal in the air. The database can be based on, e.g.,past UE measurements, or antenna specifications for identifyingelevation nulls.

In some aspects, for each region in the air, the BSs (e.g., eNB 111) cancharacterize each of location, speed, and/or direction into differentcategories such as normal and fast-fluctuation. The BS can furtherdivide the aerial region into several categories based on whatfunctionalities are typical for the region, e.g., normal,fast-fluctuation, ping-pong, dead zone. For different zones, differentenhancement procedures can be adopted which can include one or more ofthe following:

In fast-fluctuation zones, the handover parameters can be set with ascaling factor to match the anticipated cell quality change rate. Timeto trigger (TTT) can be based on speed and/or elevation and/or directionfrom the base station. Timer T310 (which is related to RLF) can be basedon speed and/or elevation and/or direction from the base station. Inping-pong zones, the serving cell can instruct the drone to increase theA3 bias, to neglect measurements from a specific set of neighbor cells,or to temporally deactivate a typical reporting mechanism based onmeasurements. In some aspects, before the drone enters a ‘dead zone’,the serving cell can alert the drone to prepare for handover. The BS canalso inform the drone of dead zones such that the drone can avoidtraveling in such areas.

In some aspects, when a serving cell knows the drone's route, theserving cell can prepare the drone's handover by sending a ‘suggested HOlist’—a list of cells the drone can consider connecting with priority.Such list can be generated by the serving cell based on routeinformation or flight path information, current height, current traveldirection and speed, and/or future route and speed as can be reported tothe serving cell by the drone. One possible enhancement is that once anycell within the list is beyond a minimal threshold, the drone canpromptly report with a modified TTT. In addition, if route informationfor longer time duration is available, the serving cell may signal inadvance to instruct the drone UE how the TTT can be adjusted along itstrajectory.

In some aspects, the serving cell may prioritize the HO transitionbefore what is needed in a traditional procedure as it can estimate inreal-time the time needed for the HO to happen.

In some aspects, dual connectivity between the drone, the source eNB,and the target eNB may be enabled as well in a fast fluctuation regionfor stability.

In some aspects, once the serving cell receives the measurement reportfrom the UE, the serving cell may send an HO request to multiple targetcells, the serving cell may combine multiple target cells HO ACK into asingle HO command, and forward such HO command to the UE. The drone UEmay select one target cell based on signal quality at the time ofreceiving the HO command. Once the UE handover to the selected targetcell is completed, the target cell can signal the serving cell that theHO is completed. The serving cell can then signal the other unusedtarget cells to release the resources.

In some aspects, the route information may be included in themeasurement report (MR) or RRC connection setup message, or other RRCmessaging. In some aspects, the route information may contain thecurrent location and final destination. In some aspects, the routeinformation may contain multiple points of the path of flying. In someaspects, the route information may be forward to the target cell uponhandover. The network may use this information to prepare the targetcell sooner and configure corresponding measurement events. As soon asthe measurement report (MR) is received by the serving cell, the servingcell can forward the HO command to the UE without waiting for X2 delayof the HO request and acknowledgment (ACK). In some aspects, the networkmay also prepare the target cell along the flying path and send HOcommand in advance to the UE without measurement report. The advance HOcommand may contain an HO trigger condition where the UE will notexecute the HO immediately but rather when the condition is met, thenthe UE can perform the HO to the target cell.

Signaling

In some aspects, an information message can be sent from the drone UE tothe serving cell. More specifically, a drone can periodically (or uponrequest) include in the measurement report the following information:

Current height: For example, the height information may be encoded in1-2 bits mapping to predefined height. One example is the verticalheight can be divided into several regions such as below 40 m, 40-60,60-80, 80-100, 100-120, and above 120 m. The request message may alsocontain a request to the UE when a change of height, the drone UE toreport the elevation. In some aspects, a new measurement report may alsobe introduced with height evaluation triggering as a condition. Forexample, it is X meters higher than the last reporting, or it reaches Ymeters as an absolute value. In some aspects, one or more heightthreshold values can be communicated to the UE during the measurementcontrol configuration. The UE can then trigger reporting its aerialheight (or altitude) when such height is above a first threshold orbelow a second threshold.

Current travel direction and speed: in some aspects, the measurementreports may contain the heading direction and speed of the drone. Insome aspects, a threshold can be set to trigger this report. Forexample, a drone can only inform a BS the travel direction and speedinformation if the travel direction and/or speed will remain unchangedfor more than T0 second, or over a distance more than S0 meters, whereboth T0 and S0 are threshold values set by the serving cell. In someaspects, a drone can further report its future route and speed to itsserving cell, if such information is available.

FIG. 3 illustrates a communication flow diagram 300 for handover usingmeasurement reporting with enhanced signaling design for drones in acellular network, in accordance with some aspects. Referring to FIG. 3,the communication flow illustrated in diagram 300 can take place inconnection with a handover procedure between a drone UE 101, a sourceeNB 302, and a target eNB 304. At operation 306, measurement control andconfiguration signaling 308 (or 190A in FIG. 1A) can be communicatedfrom the source eNB 302 to the drone UE 101. The configuration signaling308 can include, for example, one or more thresholds for triggeringdrone height or altitude measurements for inclusion in a measurementreport. At operation 310, the measurement report 312 can be generatedbased on the configuration information 308.

At operation 314, the source eNB 302 can perform a handover decision 314based on the received measurement report 312. At operation 316, thesource eNB 302 communicates a handover request 318 to the target eNB304, passing necessary information to prepare the HO at the target side(UE X2 signalling context reference at source eNB, UE S1 EPC signallingcontext reference, target cell ID, KeNB*, RRC context including theC-RNTI of the UE in the source eNB, AS-configuration, E-RAB context andphysical layer ID of the source cell, and short MAC-I for possible RLFrecovery). UE X2/UE S1 signaling references enable the target eNB toaddress the source eNB and the EPC. The E-RAB context includes necessaryRNL and TNL addressing information, and QoS profiles of the E-RABs.

At operation 320, admission control may be performed by the target eNB304 dependent on the received E-RAB QoS information to increase thelikelihood of a successful HO, if the resources can be granted by targeteNB. The target eNB configures the required resources according to thereceived E-RAB QoS information and reserves a C-RNTI and optionally aRACH preamble. The AS-configuration to be used in the target cell caneither be specified independently (i.e. an “establishment”) or as adelta compared to the AS-configuration used in the source cell (i.e. a“reconfiguration”).

At operation 322, the target eNB 304 communicates a handover requestacknowledgment 324 to the source eNB 302. At operation 326, the sourceeNB 302 communicates a handover command 328 to the drone UE 101. Morespecifically, the target eNB 304 can generate the RRC message to performthe handover, i.e. RRCConnectionReconfiguration message including themobilityControlInformation, to be sent by the source eNB 302 towards thedrone UE 101. The source eNB 302 performs the necessary integrityprotection and. ciphering of the message.

The drone UE 101 receives the RRCConnectionReconfiguration message withnecessary parameters (i.e. new C-RNTI, target eNB security algorithmidentifiers, and optionally dedicated RACH preamble, target eNB SIBs,etc.) and is commanded by the source eNB 302 to perform the HO. IfRACH-less HO is configured, the RRCConnectionReconfiguration includestiming adjustment indication and optionally preallocated uplink grantfor accessing the target eNB. If the preallocated uplink grant is notincluded, the UE should monitor PDCCH of the target eNB to receive anuplink grant. The UE does not need to delay the handover execution fordelivering the HARQ/ARQ responses to source eNB.

At operation 330, handover completion 332 can take place and can includemultiple operations such as synchronization, uplink allocation, RRCconnection reconfiguration completion report, and so forth in order tocomplete their handover to the target eNB 304.

FIG. 4 illustrates a block diagram of an example measurement report thatcan be configured using enhanced signaling design for drones, inaccordance with some aspects. Referring to FIG. 4, there is illustrateda more detailed view of the measurement report 312 generated during thedrone handover process described in FIG. 3. More specifically, themeasurement report 312 can include the following information associatedwith the drone UE 101: current height information (or altitude) 402,route or flight path information 404, travel/flight directioninformation 412, and travel velocity information 414. The routeinformation 404 can further include a current location information 406,a final destination location 408, as well as one or more waypoints orintermediate locations 410 along the route from the current location tothe final destination. Other drone-related information can also beincluded in the measurement report 312, which information can be used tofacilitate handover between cells.

UE-Initiated Mobility Enhancements

In some aspects, the drone UE can collect geographical and BSinformation from higher layers, such as application servers, and utilizesuch information to enhance handover. Information gathered from higherlayers can include 3-dimensional geographical coverage holes, BSlocations and elevation nulling angles, and so forth. Based on thecollected information, the drone UE can perform various handoverenhancements.

In some aspects, the drone UE can deter mine locally whether to shortenor increase TTT for handover measurement based on its location andheight estimate. Furthermore, the drone UE can independently determinethe measurement granularity. For example, based on the database (e.g.,194A), the drone UE can obtain measurement more frequently from certaincandidate cells. Also, the drone UE can measure the links betweencertain “good” (or “optimal”) cells identified as such in the database.

In some aspects, the drone UE can predict whether it is currently in acoverage hole (or a dead zone) based on its own geolocation, angledirection, and past channel quality measurement, as well as a databasecontaining BS information. Once the drone UE detects that it is in adead zone, it can navigate away from the dead zone. Also, the drone caninform the BS of a potential handover attempt.

In some aspects, the drone UE 101 can utilize higher-layer informationto obtain a signal region map from an application layer or a networklayer, and locally store and update the database (e.g., 194A).

FIG. 5 illustrates a block diagram of a communication device such as anevolved Node-B (eNB), a new generation Node-B (gNB), an access point(AP), a wireless station (STA), a mobile station (MS), or a userequipment (UE) such as a drone, in accordance with some aspects and toperform one or more of the techniques disclosed herein. In alternativeaspects, communication device 500 may operate as a standalone device ormay be connected (e.g., networked) to other communication devices.

Circuitry (e.g., processing circuitry) is a collection of circuitsimplemented intangible entities of the device 500 that include hardware(e.g., simple circuits, gates, logic, etc.). Circuitry membership may beflexible over time. Circuitries include members that may, alone or incombination, perform specified operations when operating. In an example,the hardware of the circuitry may be immutably designed to carry out aspecific operation (e.g., hardwired). In an example, the hardware of thecircuitry may include variably connected physical components (e.g.,execution units, transistors, simple circuits, etc.) including amachine-readable medium physically modified (e.g., magnetically,electrically, moveable placement of invariant massed particles, etc.) toencode instructions of the specific operation.

In connecting the physical components, the underlying electricalproperties of a hardware constituent are changed, for example, from aninsulator to a conductor or vice versa. The instructions enable embeddedhardware (e.g., the execution units or a loading mechanism) to createmembers of the circuitry in hardware via the variable connections tocarry out portions of the specific operation when in operation.Accordingly, in an example, the machine-readable medium elements arepart of the circuitry or are communicatively coupled to the othercomponents of the circuitry when the device is operating. In an example,any of the physical components may be used in more than one member ofmore than one circuitry. For example, under operation, execution unitsmay be used in a first circuit of a first circuitry at one point in timeand reused by a second circuit in the first circuitry, or by a thirdcircuit in a second circuitry at a different time. Additional examplesof these components with respect to the device 500 follow.

In some aspects, device 500 may operate as a standalone device or may beconnected (e.g., networked) to other devices. In a networked deployment,the communication device 500 may operate in the capacity of a servercommunication device, a client communication device, or both inserver-client network environments. In an example, the communicationdevice 500 may act as a peer communication device in peer-to-peer (P2P)(or other distributed) network environment. The communication device 500may be a UE, eNB, PC, a tablet PC, a STB, a PDA, a mobile telephone, asmartphone, a web appliance, a network router, switch or bridge, or anycommunication device capable of executing instructions (sequential orotherwise) that specify actions to be taken by that communicationdevice. Further, while only a single communication device isillustrated, the term “communication device” shall also be taken toinclude any collection of communication devices that individually orjointly execute a set (or multiple sets) of instructions to perform anyone or more of the methodologies discussed herein, such as cloudcomputing, software as a service (SaaS), and other computer clusterconfigurations.

Examples, as described herein, may include, or may operate on, logic ora number of components, modules, or mechanisms. Modules are tangibleentities (e.g., hardware) capable of performing specified operations andmay be configured or arranged in a certain manner. In an example,circuits may be arranged (e.g., internally or with respect to externalentities such as other circuits) in a specified manner as a module. Inan example, the whole or part of one or more computer systems (e.g., astandalone, client or server computer system) or one or more hardwareprocessors may be configured by firmware or software (e.g.,instructions, an application portion, or an application) as a modulethat operates to perform specified operations. In an example, thesoftware may reside on a communication device-readable medium. In anexample, the software, when executed by the underlying hardware of themodule, causes the hardware to perform the specified operations.

Accordingly, the term “module” is understood to encompass a tangibleentity, be that an entity that is physically constructed, specificallyconfigured (e.g., hardwired), or temporarily (e.g., transitorily)configured (e.g., programmed) to operate in a specified manner or toperform part or all of any operation described herein. Consideringexamples in which modules are temporarily configured, each of themodules need not be instantiated at any one moment in time. For example,where the modules comprise a general-purpose hardware processorconfigured using software, the general-purpose hardware processor may beconfigured as respective different modules at different times. Thesoftware may accordingly configure a hardware processor, for example, toconstitute a particular module at one instance of time and to constitutea different module at a different instance of time.

Communication device (e.g., UE) 500 may include a hardware processor 502(e.g., a central processing unit (CPU), a graphics processing unit(GPU), a hardware processor core, or any combination thereof), a mainmemory 504, a static memory 506, and mass storage 507 (e.g., hard drive,tape drive, flash storage, or other block or storage devices), some orall of which may communicate with each other via an interlink (e.g.,bus) 508.

The communication device 500 may further include a display device 510,an alphanumeric input device 512 (e.g., a keyboard), and a userinterface (UI) navigation device 514 (e.g., a mouse). In an example, thedisplay device 510, input device 512 and UI navigation device 514 may bea touchscreen display. The communication device 500 may additionallyinclude a signal generation device 518 (e.g., a speaker), a networkinterface device 520, and one or more sensors 521, such as a globalpositioning system (GPS) sensor, compass, accelerometer, or anothersensor. The communication device 500 may include an output controller528, such as a serial (e.g., universal serial bus (USB), parallel, orother wired or wireless (e.g., infrared (IR), near field communication(NFC), etc.) connection to communicate or control one or more peripheraldevices (e.g., a printer, card reader, etc.).

The storage device 507 may include a communication device-readablemedium 522, on which is stored one or more sets of data structures orinstructions 524 (e.g., software) embodying or utilized by any one ormore of the techniques or functions described herein. In some aspects,registers of the processor 502, the main memory 504, the static memory506, and/or the mass storage 507 may be, or include (completely or atleast partially), the device-readable medium 522, on which is stored theone or more sets of data structures or instructions 524, embodying orutilized by any one or more of the techniques or functions describedherein. In an example, one or any combination of the hardware processor502, the main memory 504, the static memory 506, or the mass storage 516may constitute the device-readable medium 522.

As used herein, the term “device-readable medium” is interchangeablewith “computer-readable medium” or “machine-readable medium”. While thecommunication device-readable medium 522 is illustrated as a singlemedium, the term “communication device-readable medium” may include asingle medium or multiple media (e.g., a centralized or distributeddatabase, and/or associated caches and servers) configured to store theone or more instructions 524.

The term “communication device-readable medium” is inclusive of theterms “machine-readable medium” or “computer-readable medium”, and mayinclude any medium that is capable of storing, encoding, or carryinginstructions (e.g., instructions 524) for execution by the communicationdevice 500 and that cause the communication device 500 to perform anyone or more of the techniques of the present disclosure, or that iscapable of storing, encoding or carrying data structures used by orassociated with such instructions. Non-limiting communicationdevice-readable medium examples may include solid-state memories andoptical and magnetic media. Specific examples of communicationdevice-readable media may include: non-volatile memory, such assemiconductor memory devices (e.g., Electrically Programmable Read-OnlyMemory (EPROM), Electrically Erasable Programmable Read-Only Memory(EEPROM)) and flash memory devices; magnetic disks, such as internalhard disks and removable disks; magneto-optical disks; Random AccessMemory (RAM); and CD-ROM and DVD-ROM disks. In some examples,communication device-readable media may include non-transitorycommunication device-readable media. In some examples, communicationdevice-readable media may include communication device-readable mediathat is not a transitory propagating signal.

The instructions 524 may further be transmitted or received over acommunications network 526 using a transmission medium via the networkinterface device 520 utilizing any one of a number of transferprotocols. In an example, the network interface device 520 may includeone or more physical jacks (e.g., Ethernet, coaxial, or phone jacks) orone or more antennas to connect to the communications network 526. In anexample, the network interface device 520 may include a plurality ofantennas to wirelessly communicate using at least one ofsingle-input-multiple-output (SIMO), MIMO, ormultiple-input-single-output (MISO) techniques. In some examples, thenetwork interface device 520 may wirelessly communicate using MultipleUser MIMO techniques.

The term “transmission medium” shall be taken to include any intangiblemedium that is capable of storing, encoding or carrying instructions forexecution by the communication device 500, and includes digital oranalog communications signals or another intangible medium to facilitatecommunication of such software. In this regard, a transmission medium inthe context of this disclosure is a device-readable medium.

A communication device-readable medium may be provided by a storagedevice or other apparatus which is capable of hosting data in anon-transitory format. In an example, information stored or otherwiseprovided on a communication device-readable medium may be representativeof instructions, such as instructions themselves or a format from whichthe instructions may be derived. This format from which the instructionsmay be derived may include source code, encoded instructions (e.g., incompressed or encrypted form), packaged instructions (e.g., split intomultiple packages), or the like. The information representative of theinstructions in the communication device-readable medium may beprocessed by processing circuitry into the instructions to implement anyof the operations discussed herein. For example, deriving theinstructions from the information (e.g., processing by the processingcircuitry) may include: compiling (e.g., from source code, object code,etc.), interpreting, loading, organizing (e.g., dynamically orstatically linking), encoding, decoding, encrypting, unencrypting,packaging, unpackaging, or otherwise manipulating the information intothe instructions.

In an example, the derivation of the instructions may include assembly,compilation, or interpretation of the information (e.g., by theprocessing circuitry) to create the instructions from some intermediateor preprocessed format provided by the machine-readable medium. Theinformation, when provided in multiple parts, may be combined, unpacked,and modified to create the instructions. For example, the informationmay be in multiple compressed source code packages (or object code, orbinary executable code, etc.) on one or several remote servers. Thesource code packages may be encrypted when in transit over a network anddecrypted, uncompressed, assembled (e.g., linked) if necessary, andcompiled or interpreted (e.g., into a library, stand-alone executableetc.) at a local machine, and executed by the local machine.

Although an aspect has been described with reference to specificexemplary aspects, it will be evident that various modifications andchanges may be made to these aspects without departing from the broaderscope of the present disclosure. Accordingly, the specification anddrawings are to be regarded in an illustrative rather than a restrictivesense. This Detailed Description, therefore, is not to be taken in alimiting sense, and the scope of various aspects is defined only by theappended claims, along with the full range of equivalents to which suchclaims are entitled.

1. (canceled)
 2. An apparatus of a user equipment (UE), the apparatuscomprising: processing circuitry, wherein to configure the UE forhandover between a source base station and a target base station usingaerial communications in a cellular network, the processing circuitry isto: decode measurement configuration information from the source basestation, the measurement configuration information including a pluralityof height thresholds associated with an aerial height of the UE; encodea measurement report for transmission to the source base station, themeasurement report including the aerial height of the UE; decode radioresource control (RRC) signaling from the source base station, the RRCsignaling including a handover command; and perform a handover from thesource base station to the target base station based on the handovercommand; and memory coupled to the processing circuitry, the memoryconfigured to store the measurement configuration information.
 3. Theapparatus of claim 2, wherein the plurality of height thresholdsincludes a first threshold associated with a first measurement reportevent, the first measurement report event triggers generation of themeasurement report when the aerial height of the UE is above the firstthreshold.
 4. The apparatus of claim 3, wherein the plurality of heightthresholds includes a second threshold associated with a secondmeasurement report event, the second measurement report event triggeringthe generation of the measurement report when the aerial height of theUE is below the second threshold.
 5. The apparatus of claim 2, whereinthe processing circuitry is to: encode UE capability configurationinformation for transmission to the source base station, the UEcapability configuration information indicating whether the UE supportsmeasurement events triggering generation of the measurement report basedon the aerial height of the UE.
 6. The apparatus of claim 2, whereingeneration of the measurement report is triggered based on one or moretriggering events associated with the plurality of height thresholds,and wherein the processing circuitry is to: encode the measurementreport to further include an information element indicating verticalvelocity of the UE.
 7. The apparatus of claim 2, wherein the processingcircuitry is further to: decode an information request from the sourcebase station; based on the information request, encode an informationresponse for transmission to the source base station, the informationresponse including flight path information for the UE.
 8. The apparatusof claim 7, wherein the flight path information includes a list ofwaypoints along the flight path of the UE.
 9. The apparatus of claim 2,wherein the processing circuitry is to: encode UE capabilityconfiguration information for transmission to the source base station,the UE capability configuration information indicating whether the UEsupports reporting of flight path information for inclusion in themeasurement report.
 10. The apparatus of claim 2, wherein the processingcircuitry is to: determine flight path information for the UE; retrieve3-dimensional signal environment properties based on the determinedflight path; and determine whether to perform the handover from thesource base station to the target base station based on the signalenvironment properties along the flight path and within a cell of thetarget base station.
 11. The apparatus of claim 2, further comprisingtransceiver circuitry coupled to the processing circuitry; and, one ormore antennas coupled to the transceiver circuitry.
 12. A non-transitorycomputer-readable storage medium that stores instructions for executionby one or more processors of a source base station configured for aerialcommunications in a cellular network, the instructions to configure theone or more processors to cause the source base station to: encodemeasurement configuration information for transmission to a userequipment (UE), the measurement configuration information including aplurality of height thresholds associated with aerial height of the UE;decode a measurement report received from the UE, the measurement reportincluding the aerial height of the UE; and encode radio resource control(RRC) signaling for transmission to the UE, the RRC signaling includinga handover command for handover from the source base station to a targetbase station, the handover command based on a handover decision usingthe measurement report; and
 13. The non-transitory computer-readablestorage medium of claim 12, wherein the plurality of height thresholdsincludes a first threshold associated with a first measurement reportevent, the first measurement report event triggers generation of themeasurement report when the aerial height of the UE is above the firstthreshold.
 14. The non-transitory computer-readable storage medium ofclaim 13, wherein the plurality of height thresholds includes a secondthreshold associated with a second measurement report event, the secondmeasurement report event triggering the generation of the measurementreport when the aerial height of the UE is below the second threshold.15. The non-transitory computer-readable storage medium of claim 12,wherein instructions configure the one or more processors to cause thesource base station to: decode UE capability configuration informationfrom the UE, the UE capability configuration information indicatingwhether the UE supports measurement events triggering generation of themeasurement report based on the aerial height of the UE.
 16. Thenon-transitory computer-readable storage medium of claim 12, whereingeneration of the measurement report is triggered based on one or moretriggering events associated with the plurality of height thresholds,and wherein the measurement report further includes an informationelement indicating vertical velocity of the UE.
 17. A non-transitorycomputer-readable storage medium that stores instructions for executionby one or more processors of a user equipment (UE) configured for aerialcommunications in a cellular network, the instructions to configure theone or more processors to cause the UE to: decode measurementconfiguration information from a source base station, the measurementconfiguration information including a plurality of height thresholdsassociated with aerial height of the UE; encode a measurement report fortransmission to the source base station, the measurement reportincluding the aerial height of the UE; decode radio resource control(RRC) signaling from the source base station, the RRC signalingincluding a handover command; and perform a handover from the sourcebase station to a target base station based on the handover command. 18.The non-transitory computer-readable storage medium of claim 17, whereinthe plurality of height thresholds includes a first threshold associatedwith a first measurement report event, the first measurement reportevent triggers generation of the measurement report when the aerialheight of the UE is above the first threshold.
 19. The non-transitorycomputer-readable storage medium of claim 18, wherein the plurality ofheight thresholds includes a second threshold associated with a secondmeasurement report event, the second measurement report event triggeringthe generation of the measurement report when the aerial height of theUE is below the second threshold.
 20. The non-transitorycomputer-readable storage medium of claim 17, wherein generation of themeasurement report is triggered based on one or more triggering eventsassociated with the plurality of height thresholds, and wherein theinstructions further configure the one or more processors to cause theUE to: encode UE capability configuration information for transmissionto the source base station, the UE capability configuration informationindicating whether the UE supports measurement events triggeringgeneration of the measurement report based on the aerial height of theUE.
 21. The non-transitory computer-readable storage medium of claim 17,wherein the instructions further configure the one or more processors tocause the UE to: decode an information request from the source basestation; based on the information request, encode an informationresponse for transmission to the source base station, the informationresponse including flight path information for the UE.